1. Field of the Invention:
The present invention relates to an improved exercise machine having components with increased resistance to movement depending upon the direction of movement. More particularly, the present invention relates to a device for simulating the paddling of a canoe and for determining the quantity and quality of work performed during an exercise session. Such an exercise device can be part of an overall program of physical conditioning in which strength and stamina may be measured over time or in comparison to other individuals.
2. Description of the Prior Art:
Exercise machines have been known in the prior art. These devices provide resistance to movement and increased the strength and stamina of the user. Rowing or paddling a canoe is an excellent form of exercise for strengthening the upper body, particularly the arms, improving cardio-vascular functions and for training for competitive events. However, it is not always convenient for an individual to paddle a canoe or to row a boat and thus attempts have been made to design an exercise machine which will simulate the paddling of a canoe or the rowing of a boat. The paddling of the canoe and the rowing of the boat have the common feature that the resistance to movement varies depending upon the direction of movement. That is, in such rowing or paddling, resistance is great during the paddle stroke but is minimal during the return stroke. Thus, exercise machines which simulate the paddling or rowing motions must provide such differential resistance.
For example, U.S. Pat. No. 228,277 to Saunders discloses an exercising machine that simulates the rowing of a boat. This patent provides a differential resistance by use of an air pump. The air pump has a working stroke that requires effort and a return stroke that is practically free of effort. However, such an air pump is costly and easily broken and is considered to be unsatisfactory.